Antisera raised against normal prostatic tissue and tissue extracts are employed to identify prostate specific substances and to detect these substances in prostatic carcinoma. In addition to immunological characterization, prostate specific substances are subjected to biochemical characterization including estimation of molecular weight and isoelectric point. The primary substances currently being investigated include a cytosol androgen receptor, acid phosphatase and an unidentified protein antigen. BIBLIOGRAPHIC REFERENCE: Investigation of Specific Antigens in Prostatic Cancer. Charles W. Moncure, Charles L. Johnston, Jr., Warren W. Koontz, Jr. and M.J. Vernon Smith. Cancer Chemotherapy Reports Part 1, Vol. 59, No. 1, Jan/Feb, 1975.